How to adjust engine idle speed in a motorcycle: Easy steps

A motorcycle's idle speed refers to how fast it rolls forward when the brake is released while the engine is running. If the motorcycle has a carburettor, the idle speed can be adjusted using the idle screw. If the motorcycle comes with fuel-injection technology, the rider can adjust the idle speed with the small knob that sticks out of the engine compartment on the left or right side of the bike.

In a bid to adjust the RPM, first check your motorcycle's user manual to find the recommended idle RPM. The ideal idle RPM for the motorcycle should be between 700-1,000 rpm. Also, in some motorcycles, there are tachometers that tell the RPM when the motorcycle's engine is on. The tachometer can be monitored to check the idle speed of the motorcycle before adjusting the idle RPM. Experts also determine the RPM settings by listening the sound and feeling the vibrations. When in idle mode, the sound of the engine should be a low buzz, instead of a high-pitched throttle.

Here are some easy steps to follow to determine and adjust the idle speed of your motorcycle.

Turn on the motorcycle

Turn the motorcycle engine on and wait for two-three minutes for the powertrain to level out. Put the kickstand down and keep the engine on. Wait at least two minutes for the engine to be hot and reach a stable temperature and speed. The idle speed can be adjusted when the bike is off as well, but it is always recommended to do it when the machine is on so the engine can adjust slowly to the changes while there's petrol running through it. In case, you are adjusting the idle speed when it is cold, let the bike run for around 10-15 minutes prior to the changes. Motorcycles come with a cold idle setting that restrict the idle speed until the powertrain gets hot.

Check RPM on tachometer

Check the idle RPM on the tachometer of the motorcycle if there is one. Check the reading on the gauge while the bike is in idle mode. If the RPM is in the acceptable idle range, it doesn't require any adjustment with the screw. If it is not in the acceptable range, determine whether you want the idle speed lower or higher.

Tighten the screw to increase idle speed

In order to increase the engine idle speed, tighten the screw clockwise. You can use a Phillips head screwdriver to turn the idle screw clockwise. Turn the screw once or twice to make minor adjustments in the idle speed, or three-four times to significantly increase the idle RPM. On some motorcycles, the screw can be adjusted by hand only. However, it is safer to use a screwdriver. On the modern sportbikes, there is usually a knob on the side of the model near the engine compartment. It can be simply turned clockwise to adjust the screw.

Loosen the screw to decrease idle speed

If the idle speed is required to be lowered, loosen the screw by rotating it counterclockwise. Turning the screw anti-clockwise will decrease the idle speed. Turn it based on how slightly or significantly you want to trim the idle speed on your motorcycle.

Check the tachometer reading

After making the adjustment, the tachometer's needle will reflect the changes. Check the tachometer after the adjustment is made through the idle screw to see if the idle RPM is within the OEM-recommended range. If it isn't, then make the adjust again using the same steps until the needle is in an acceptable location during the motorcycle's idle mode. Also, get on the motorcycle and release the brake to check how it feels after making the adjustment.

How to adjust motorcycle engine's idle speed

Step 1 :

Turn on the motorcycle

Step 2 :

Check RPM on the tachometer

Step 3 :

Tighten the screw to increase idle speed

Step 4 :

Loosen the screw to decrease idle speed

Step 5 :

Check the tachometer reading